Best transistors to resemble Inverter and AND functions?

[Enrique15]

Hi again fellows.
I come to ask for help, AGAIN.

I'm still with my IC555 alarm circuit, because now I decided to add a second speaker to the circuit, but I don't want to feed both speakers at the same time (trying not to finish up too soon the 4 batteries I'm using to feed the circuit with 6 volts).
Instead, I'll put an IC 555 timer to control the start ON of the first and second speaker, one at a time. When the 555 voltage rises to 6V, the first speaker will turn on, and when the voltage drops to zero again (in the oscillation), the first speaker will turn off while the second speaker will turn on.

And to get the second speaker turned on when the 555 drops to zero, I'll use an INVERTER to change the zero to 6 volts to start the IC 555 related to that speaker (I'm using 555 timers to make the oscillations that will get the speakers to make sound).

But the thing here is that I don't want to buy an Inverter gates IC, because I'll use only one gate. So I thought it'll be more interesting to get the inverter gate function with transistors.

So, I wanted to know if some of you that already have a lot of experience using J-FETS and MOSFETS, could give me some advice about what is better between both types for this matter. Because I'm trying that my circuit uses the least current from the batteries.

For what I see in datasheets, MOSFET is better than J-FET in this matter of using very low currents.
For example, the datasheet of an 2N4351 N-Enhancement Mosfet says:
Igss(gate leakage current)= 10pA
Idss(zero gate voltage drain current)=10nA
Id(ON)= 3mA
Sounds good to me, but I read about the problem MOSFETs have in their gates with electrostatic.

An example of J-FET: 2N4416 N-JFET
Idss(drain current at zero gate voltage)= 5mA (MIN), 15 mA (MAX)


And not to mention that I have to look up for complementary transistors to get the so mentioned Inverter Gate function.

If you can help me and tell me a couple of transistors you know that work well in complementary situation, it'll be useful for me to make the inverter function and the AND gate function as well.

I'll appreciate your help.
And thanks in advance. :spoko:

 

[Enrique15]

Is this topic ok in this forum, or should I move it to the BASIC QUESTIONS forum.....

Since no one is answering here in the analog design forum.... :sm1:


:?: :?: :?: :?: :?:


Regards.

 

[10kangstroms]

Have a look at Fairchild Tinylogic. Better than individual transistors, in my opinion. Other companies have similar logic families.

 

[nand_gates]

Hi
Here is one idea you can use. Use BC547 transistor!
Hope this helps

 

[Enrique15]

Thanks 10kangstroms for your suggestion. I will have to see if in the electronic shop they have those kind of ICs. But I'm not so sure they'll have those Fairchild tiny models.

nand_gates, thanks for your suggestion, too. But in your drawing, it seems that one of the speakers will work always, as soon as I connect the Vcc power supply. Because the collector will be at Vcc while the transistor is cut (with the 555 timer not active).

And what I planned is that no speaker will work (while having the circuit connected to Vcc), until I push a button, that will iniciate the timer. Then is when the speakers will work alternately.


Any other suggestions about MOSFETS or J-FETS to try to simulate the "behaviour" of an Inverter gate ?


P.D. By the way, how do you do to put your pics in a box that says "number of times viewed" and "file name" and "file size"......
Because when I put my pics I only see the PIC, but nothing else.....

See you later.